Crucial MX300 Limited Edition (750GB) Review

Table of Contents

Introduction, Design & Features

Crucial’s MX300 Limited Edition is a bit of a departure for the company, and it represents a changing of the guard—or is, at least, the harbinger of one—in core solid-state drive (SSD) tech.

How so? Crucial's MX-series drives have always been at the top of the company’s product stack, despite being midrange models, with the BX drives representing its value line. (When we say "Crucial," we mean the Crucial brand; Crucial is owned by memory giant Micron Technology.) The company has offered both Crucial MX100 and MX200 drives in the past, as well as lower-end Crucial BX100 and BX200 drives. Previously, the MX-series drives always used multi-level-cell (MLC) NAND flash for the chips inside the drive, which is considered, if you will, the "good stuff" in the consumer-SSD world. MLC has great endurance and performance, and it's used in most high-end SSDs. (For more on key SSD jargon, check out our feature Buying a Solid-State Drive: 20 Terms You Need to Know.)

Meanwhile, the value segment of the market has begun to favor less-expensive triple-layer-cell (TLC) NAND flash, which is a trend Samsung started back in 2013 with its SSD 840 EVO drives. Back then, TLC NAND was something of an untried X-factor, and until then it had been considered less than suitable for consumer SSDs due to slow write times and middling endurance. Despite some hiccups along the way with the SSD 840 EVO's performance, the SSD 840 EVO was a pioneering drive. Ultimately, it and the other early TLC-based SSDs that followed showed that TLC NAND drives can be about as fast as drives with MLC NAND while also offering competitive endurance for the way consumers use SSDs. All of a sudden, TLC NAND was a viable solution, offering fast-enough performance at a lower cost than MLC drives.

It came at the right time, too, because SSD performance had already begun to plateau due to the aging Serial ATA 3.0 interface most SSDs used. As a result, consumers started to pay closer and closer attention to price when shopping for a SATA-interface SSD. This set the stage for a flurry of TLC SSDs, as one by one every major SSD maker offered one as a low-cost alternative to its flagship MLC-based drives.

It’s against this backdrop—of TLC being the value leader of late—that the Crucial MX300 emerged. Despite its MX branding, it is actually a TLC drive. That's why we referred to it as a "changing of the guard" of sorts, as it’s the first time a company has used TLC NAND in one of its ostensibly higher-end drives. To us, this suggests that the technology has advanced to the point where TLC NAND now is almost as good as MLC in certain situations—but especially in the world of SATA drives. This makes sense to us, because as we saw with Samsung's SSD 850 EVO and SSD 850 Pro, in many cases the EVO drive (which uses TLC NAND modules) is a tad faster than the Pro drive, yet costs a bit less.

In short: TLC has finally arrived.

Another interesting aspect of the MX300 SSD: It’s the second major consumer SSD to hit the market that uses "3D" NAND flash, in which the bits are arranged in rows that are stacked vertically on top of one another. (Intel released a few 3D NAND-based drives earlier this year, but they were resolutely focused on enterprise use.) This approach allows for significantly greater storage density compared to the conventional "planar" approach, in which storage cells are arranged side by side only. Since the cells are now stacked on top of each other, it's possible to employ larger cells, which translates into improved performance and endurance. Previously, the only other drives to use 3D NAND were the ones in Samsung's two SSD 850 series, which are widely considered to be among the best SATA-based SSDs available.

Also unusual about the MX300: It’s available in only one capacity, 750GB. That's where the "Limited Edition" moniker comes in, though Micron/Crucial made no claims that the 750GB version of this drive was produced in small numbers or otherwise genuinely "limited." (Indeed, in the briefing we were given pre-release, Crucial's formal response to why this is a Limited Edition SSD was: "We're eager to showcase the speed and reliability of new Micron 3D NAND, and couldn't wait to debut it in a large and affordable capacity." All well and good, but not really an answer.)

This is an unprecedented capacity to launch a drive at, as manufacturers have practically always started out with the smaller capacities (typically 128GB, 256GB, and 500GB, or close analogues to those), and perhaps a higher-capacity drive at around a terabyte. The availability of drives at more than 500GB is never a given in any particular line.

Crucial is softening the impact of this launch at high capacity, though, by offering this SSD at a relatively low $199.99. Since 750GB is not a standard SSD capacity, it’s not possible to do a side-by-side price comparison, but the cost per gigabyte is 26 cents, one of the lowest we’ve seen at launch in a drive of any capacity. By comparison, the 500GB version of the Samsung SSD 850 EVO was around $150 at this writing, which works out to about 30 cents per gig.

As far as specs go, the MX300 is rated to provide up to 530MB per second in sequential read speeds and 510MB per second for sequential writes. For IOPS, which is a random read/write spec, the drive is capable of hitting 92K read operations and 83K write operations, just a smidge on the low side but nothing you're likely to notice lacking in day-to-day drive use.

One area in which the Crucial MX300 blows away its predecessors is in rated endurance. Crucial/Micron rates the drive for 220TB of writes, which an average consumer would never be able to accomplish in his or her PC's lifetime. To put it into perspective, the just-released Samsung SSD 750 EVO, which we are in the process of reviewing, is also a TLC drive, and it has a write-endurance rating of just 70TB. And the Samsung SSD 850 EVO, also using 3D TLC NAND, has an endurance rating of 150TB in its 500GB version. So the Crucial MX300 is the new class leader when it comes to longevity. The reason why these drives can ostensibly last so long is due to the 3D NAND, which allows the manufacturer to use a larger fabrication process than with planar NAND. That means the cells themselves can be physically larger (there's more room on the die for bigger cells, since you can "build up"), and these can last longer than cells that have been shrunk by the forward march of technology. (Larger cells tend to be less prone to leakage and other endurance-related issues exacerbated by packing 'em in.)

In terms of technology, the MX300 has all the same stuff found in Crucial's previous MX200 drive that helps boost performance and improve data integrity. For starters, it features its RAIN technology, which stands for Redundant Array of Independent NAND. This allows the drive’s controller to sprinkle copies of data across the drive as backup in case one piece of memory goes kaput. The MX300 also features Crucial Dynamic Write Acceleration, which is how it is able to get around TLC NAND’s inherently slower write performance. It does this by dynamically assigning NAND flash on the drive to be an SLC-like cache, so the controller can effectively treat a chunk of TLC NAND like SLC NAND on the fly, writing one bit per cell instead of three. Because of this, the cache it creates can be only so large, so as a rule it’s usually a good idea to avoid using a TLC drive if you have to perform very large writes often. (By "large," we’re talking over 10GB.)

The MX300 also includes support for AES 256-bit hardware encryption, which has been a feature of previous MX SSDs, as well. Crucial’s Momentum Cache feature is also available via the included Storage Executive software utility; it uses system DRAM as a cache. It’s similar to Samsung’s Rapid Mode and is useful for bursts of data, but not sequential or random operations.

The drive’s sparse packaging includes a 2.5mm-thick plastic filler/adapter that lets you install the drive in laptops that require a 9.5mm-thick drive. Also in there is a serial key for Acronis True Image HD, a software utility that will help you clone your existing drive to the Crucial MX300.

The drive includes a three-year warranty, which is typical among midrange SSDs. It is worth pointing out, however, that the Samsung SSD 850 EVO, which is this drive’s most direct competitor, comes with a five-year warranty. Given that the write-endurance rating is so high on the MX300, we'd have hoped to see the same warranty length on this drive as on the Samsung (or a longer one).

With the basics out of the way, let's take a closer look at the included software package.

Software

Micron/Crucial is one of the SSD makers that has the resources to ship a full-featured software utility with its SSDs, which adds a bit of value. As we’ve said in other reviews of SATA SSDs, most users can install an SSD and ignore whatever software package comes with it, and they’ll be just fine. However, if you are the kind of user who wants to know the details of the drive from time to time, or who tweaks performance, these software packages are quite valuable.

Let’s take a closer look at what Crucial has to offer this time around. The application, which you download from the company's support site, is called Storage Executive.

The main window of the interface provides almost all of the information you would ever need to know, including the drive’s health, the free space, and whether the firmware is up to date. It also reports some core information about your PC, including the amount of physical memory being used and the current size of the virtual-memory pool. You can’t do anything directly from this window with this information, but it can be useful if you’re trying to diagnose sluggish system behavior.

The Drive Details tab provides information similar to what was shown previously, only with a bit more detail. The most interesting nugget of info here: It shows how much data has been written to the drive, a useful metric to see how much "life" is left in an SSD before it might begin to degrade and take cells out of commission.

Most SSD software utilities have a tab like this that displays S.M.A.R.T. info, but few consumers will have a clue what to do with this information. (Even we have to do our homework to remind ourselves how to read these tables.) Also, S.M.A.R.T. is supposed to warn you when any of the values exceed safe thresholds. That usually takes place upon boot, so the data in this table will be ignore-able by most folks.

This window just lets you update the drive’s firmware. It’s one of the few windows that are mandatory for a software package like this, as firmware updates are released to fix major bugs. (Most SSDs, with luck, will never need one.)

The equivalent of a secure-erase feature, this tab wipes the drive of all data and refreshes all the cells so none of the data is recoverable. It can be used to return the drive to out-of-box status or if you want to transfer ownership of the drive to another person and don’t want your data to be even conceivably recoverable. It’s a useful utility but something most of us would use only rarely.

The PSID Revert function is for people who choose to enable the hardware encryption offered by this drive. If you forget your password, you can have the software create a new encryption key, which typically requires the drive to be wiped so it can be re-encrypted.

As we mentioned earlier, Crucial’s Momentum Cache is similar to Samsung’s Rapid Mode, in that it allows the SSD to use the system’s DRAM as a cache. Here’s how Micron/Crucial describes this feature: "Micron's Momentum Cache is an intelligent software driver that dynamically leverages unused system resources to enhance burst performance on supported Micron and Crucial solid state drives (SSDs) in Windows operating systems. Momentum Cache is not restricted by SATA bus throughput limitations; instead, it uses additional DRAM bandwidth to achieve increased burst performance.”

It goes on to say that many SSDs have better read performance than write performance, especially on lower-capacity SSDs in a given line, and that, “…Momentum Cache addresses this inefficiency by caching nearly all writes being transferred to the SSD. The writes are transferred from the cache to the SSD during periods of lower drive activity, providing a buffer to spread intense workloads over time and enabling improved burst performance.”

If you have enough system memory that you won’t miss a gigabyte, we’d enable it, since it promises better performance. But it’s hard to quantify its real-world impact on performance. In some benchmark tests, it kicks back gaudy numbers, as it effectively measures the speed of the RAM, but in everyday use the effect is generally imperceptible. For example, running our Crystal DiskMark benchmark test (more on which on the next page) with Momentum Cache enabled shot back numbers that far exceeded the theoretical limits of the SATA interface. In PCMark 8's Storage test, though, a holistic measure of actual day-to-day tasks, the MX300 scored 4,997, easily within the margin of error of the 4,969 the drive scored without it enabled.

Still, if you have system memory to spare (say, more than 8GB), it won’t hurt performance, though you do run the risk of losing some data in-flight if it's sitting in RAM when there's a power outage. That's a risk only you can weigh: Do you run your PC on a UPS or other battery backup, and how often do you lose power where you are?